Beginning chiefly in the 1990's, automobiles having liftgates began to incorporate powered liftgate assemblies, so that the liftgate could be opened and closed at the touch of a button. Typically, powered liftgate assemblies require a compact design, and frequently implement a power strut to open and close the liftgate. Given size constraints of the system, power struts are typically very compact and lightweight in design, and consequently sometimes use plastic or other polymer materials for the gears that communicate power between a motor and the strut to open the liftgate. Though these materials and the related configuration are sufficient for use of the power strut as intended, they may fail if subjected to excessive forces encountered during foreseeable misuse (e.g., when the liftgate is manually opened or closed at high speed and rapidly stopped, rather than powered to open or close as designed). In particular, application of excessive force can result in high-speed conditions for rotating parts, which are then frequently driven to a hard-stop subsequently damaging the rotating parts, the motor, the struts, or a combination of these components.
Typically, approaches to overcoming problems associated with the durability of a power strut are focused on strengthening the materials and components of the strut itself. Such an approach is hindered by the physical constraints of the power strut system: requiring systems to be very compact and lightweight in design. There is a need, therefore, to overcome the foregoing problems while at the same time providing a lightweight, compact design that can simultaneously provide enhanced durability to a power strut while also being economical to manufacture, easy to use, and durable.